By Ambika Ahuja
BANGKOK (Reuters) - Severe flooding and mudslides in southern Thailand have killed 21 people, stranded thousands of tourists and threatened to delay shipments of rubber in the world's largest rubber-producing country, authorities said on Wednesday.
Trains to the region have been canceled and three airports have been shut, including one on the resort island of Koh Samui which is popular among Thai and foreign tourists. Nakhon Si Thammarat and Surat Thani airports have also been closed.
Thailand's navy sent four vessels including an amphibious landing craft with on-board helicopters to the rubber-rich region to deliver supplies and rescue tourists and villagers in areas severely hit.
"The army and the navy are working together to help those stranded and evacuate others who live in areas at risk of a mudslide," Satit Wongnongtoey, a minister in the prime minister's office, told Reuters.
"More rain is expected in the next few days."
The floods are having only a limited impact on rubber production in the region, but shipment of between 1,000 and 1,500 tonnes of smoked rubber sheet could be delayed as a result of transportation problems, industry officials said.
Rubber shipment delays of several weeks were possible. The southern region supplies 90 percent of the 3.2 million tonnes produced annually in Thailand, the world's biggest producer and exporter.
"Small producers along the upper south, who need to carry rubber by road to be shipped from Bangkok's port are facing disruption as roads are cut off," Prapas Uernontat, secretary general of the Thai Rubber Association told Reuters.
However, the impact on production will probably be limited as farmers stopped tapping trees for rubber in late February in anticipation of normally dry weather at this time of year.
Nearly a million people have been affected by unseasonably heavy downpours across the region.
Mudslides were reported in three areas in Krabi province. At least 10 people were killed in one village, with at least 10 others missing.
Wiboon Sangruanpong, director-general of the Department of Disaster Prevention and Mitigation, told Reuters it was too soon to assess the full damage and said more mudslides were possible in the coming days.
(Additional reporting by Apornrath Phoonphongphiphat; Editing by Martin Petty and Jeremy Laurence)